3D Printing Case Study: Stratasys Direct Manufacturing

Ultrasonic cleaning speeds up production for 3D printing prototype

Making the switch from manual to ultrasonic cleaning is paying big benefits for Stratasys Direct Manufacturing, the largest dedicated provider of additive manufacturing/3D printing, rapid prototyping, tooling and injection molding services in North America. The company creates prototype parts for a wide range of industries including military, aerospace, medical, automotive, petrochemical, quick cast foundry, oil and gas exploration, and others.

One of the 3D printing processes, fuse deposition modeling or FDM, is similar in concept to that of regular printing. Instead of putting ink on paper, 3D printing puts down layer upon layer of material, such as ABS (a thermoplastic), nylon 12, and ULTEM™ resin, to create three-dimensional end products. No more milling or turning a block of plastic to create the product you need. 3D printing enables firms to build full-size prototype parts of any shape from a variety of materials without having to invest in expensive set-up and machining. Products that are intricate or complex can be digitally designed and produced using 3D printing, eliminating the need for assembly.

Although 3D printing enables products to be produced on-the-spot and on-demand, it doesn’t eliminate the need to clean products once they have been produced. Many prototype parts rely on a resin support mold during production to maintain the shape of the product as it is being built and hardened. Once production is complete, the support material must be removed. The more complicated the part, the more difficult it can be to remove the support material without causing damage to the part. For example, technicians may be tempted to use a sharp tool to dig out support material left behind after a jet wash, which might damage the part.

Stratasys Direct Manufacturing traditionally cleaned its 3D prototype parts using a heated circulating bath washer, or by manually breaking or cutting off the support material. Although the method chosen for cleaning was dependent upon the composition of the part, neither option offered an advantage in terms of the time needed for cleaning. Not only were both methods extremely slow, but hand cutting was very labor intensive. Removing soluble support material from larger parts could take as long as 24 hours with a heated circulating washer, when there are customers waiting for their prototypes or for production run items.

Frustrated with the length of time it took to remove support material from 3D parts, the company’s executive team, began to search the Internet for a faster solution. That’s when Stratasys Direct Manufacturing found the website for Omegasonics, a leading manufacturer of ultrasonic cleaning systems.

Ultrasonic cleaners use ultrasound waves to produce millions of microscopic bubbles per second that methodically remove support material from 3D prototyped parts, one layer at a time. Each of the bubbles contains vacuum pressure, and the scrubbing action produced by the vibrating molecules, called cavitation, dissolves the resin support mold from the prototype part without causing any damage to the part itself. Since the ultrasonic waves are transmitted evenly through the cleaning fluid, even hard to reach areas like blind holes and tiny cavities are thoroughly cleaned.

When Stratasys Direct Manufacturing realized that Omegasonics units had the potential to clean the materials it uses — ABS, polycarbonate, nylon 12 and more — regardless of the part’s geometry and complexity, they were intrigued.

Because Omegasonics happened to be located in a neighboring community, representatives from Stratasys Direct Manufacturing were able to test the ultrasonic cleaning process right at the Omegasonics facility. Stratasys Direct Manufacturing quickly recognized that the fast, gentle nature of ultrasonic cleaning would make it extremely effective in removing support structure from 3D prototyped parts. In fact, the test cleanings went so well that Stratasys Direct Manufacturing was prepared to order an Omegasonics SST4030 ultrasonic cleaning machine within a week of the demonstration. Once the requisition was approved and the equipment was up and running on site, Stratasys Direct Manufacturing experienced an ROI of less than four months.

“It used to take a full day to manually remove support material from some 3D parts,” said Armen Boyajyan, Product Finishing Manager, of Stratasys Direct Manufacturing. “Now we just put the parts into the ultrasonic cleaner and do something else while they’re being cleaned. After three hours, we have nice, clean parts.”

Stratasys Direct Manufacturing bought the SST4030, the largest ultrasonic support structure cleaning system available along with a unique parts basket design that ensures parts are fully submerged in the ultrasonic bath for maximum cleaning throughout the entire cleaning cycle. According to Bill Bryan, Product Manager at Stratasys Direct Manufacturing, ultrasonic cleaning has delivered additional benefits beyond faster cleaning times.

“We’ve been able to reassign three full-time workers from the cleaning process to other revenue generating activities,” Mr. Bryan said. “And because parts are clean in just a few hours, we can deliver them to clients a day sooner, which enables us to generate revenue more quickly.”

The company is so pleased with the results that it plans to purchase three more units in the coming year. Since one ultrasonic machine helps the company clean parts four times faster, three additional machines increases their speed by 400%.

Ultrasonic cleaning works so well in many cases, that companies see as much as a 10:1 reduction in labor when they make the switch from manual cleaning. There’s just no longer a need to keep as many employees dedicated strictly to parts cleaning. Even training an ultrasonic equipment operator is quick and easy.

Built with ultra-reliable solid state components, Omegasonics ultrasonic units feature an illuminated, user-friendly control panel; digital temperature control; digital timer-controlled ultrasound; large tank capacity; stainless steel drain valve, insulated tank for reduced noise, and more. These plug-and-play units are easy to use, designed for the office environment, and require no regular maintenance except for changing the washing fluid when the pH drops below its effective rating.

To learn more about Stratasys Direct Manufacturing, visit www.StratasysDirect.com.